Plastic paint brushes



June 6, 1967 J. LAURIZIO PLASTIC PAINT BRUSHES 2 Sheets-Sheet 1 FiledSept. 30, 1964 II/IA? l/lfl'lfi'lm l E m INVENTOH 1 (/EEZM/flfl Laue/2mBY C a ATTORNEY June 1967 J. LAURIZIO PLASTIC PAINT BRUSHES 2Sheets-Sheet S Filed Sept. 30, .1964

INVENTOR ATTORNEY United States Patent M 3,323,162 PLASTIC PAINT BRUSHESJeremiah Laurizio, New Providence, NJ., assignor to American Flange &Manufacturing Co., Inc., New York, N.Y., a corporation of Delaware FiledSept. 30, 1964, Ser. No. 400,395 4 Ciairns. (Cl. 15-193) This inventionrelates to an improvement in the manufacture of brushes and isparticularly concerned with an improved construction for paint brushesof the type in which the handle and ferrule component parts thereof aremolded ofa synthetic plastic material.

In the manufacture of paint brushes it has been the practice for manyyears for the bristles to have their inner ends held in what is commonlytermed a knot, and for this knot to be mounted in a sheet metal ferrulewhich, in turn, is fastened to a wooden handle by nails, pins orequivalent fastening means. The ever increasing popularity of usingsynthetic plastic material for manufacturing a wide variety of productshas prompted a number of manufacturers to attempt to develop a paintbrush constructed in its entirety from synthetic plastic materials.However, none of these previous efforts has developed such a paint brushthat can successfully compete with the prior wooden handle paintbrushes. A number of problems present themselves in the development of asuccessful all plastic brush construction. First of all, an acceptablebrush must satisfactorily withstand the severe abuse imposed by therigorous mechanical action of normal handling. Perhaps just asimportant, an acceptable brush must not be adversely effected in any wayby prolonged submersion in any of a wide range of commercial solvents,cleaners, thinners, and the like, commonly employed in the paintingfield. Even occasional partial failure in either of the above mentionedrespects, such as might be indicated by bristles coming out or looseningof the brush parts, would completely preclude acceptance by the trade.Also not to be overlooked is the fact that in order for an all plasticbrush to compete economically with existing wood and metalconstructions, it must lend itself to a simple, relatively high speed,injection molding operation. The brush construction of this inventionhas overcome the problems encountered in the prior efforts to produce anall plastic paint brush and is believed to be a substantial improvementthereover.

A significant obstacle that has heretofore presented itself in attemptsto manufacture an all plastic brush construction is the absence of somesimple effective means for permanently securing the ferrule to the brushhandle. Improved structural qualities have been found to reside in abrush construction wherein a rigid interlocking connection is formedbetween the handle and the bristles by means of a mass of thermosettingplastic resin. The manufacture of this construction is carried out bycovering the inner ends of the bristles, supported within the ferrule,with a mass of semi-liquid synthetic resin. Upon insertion of the handleend within the ferrule, means suitably formed thereon are embedded inthe resin, thereby providing a mechanical interlock between the handleand the bristle knot upon the subsequent curing and hardening of theresin. In the prior efforts to produce an all plastic paint brush theferrule is secured to the handle and to the bristle knot by relianceupon the adhesion of the synthetic resin between the knot and theinterior surface of the ferrule. However, extensive testing has proventhis bond to be inadequate particularly under severe use conditionswhere the brush is subjected to the swelling and other deleteriouseffects of common commercial solvents used in the painting field.

The all plastic brush of this invention successfully overcomes this andother problems in providing an improved construction wherein the brushferrule is so formed as to be securely and permanently held ininterlocking engage- 3,323,162 Patented June 6, 1967 ment with thehandle and with the bristle knot. This has been accomplished withoutreliance upon either the adhesive quality of the synthetic resin or uponseparately formed and applied fasteners. Furthermore this interlockingengagement is such as to prevent movement of the ferrule away from thehandle and bristle knot not only in a longitudinal direction but also ina lateral direction hence preventing separation of the brush parts byforces causing expansion of the ferrule such as those exerted by theswelling action on the parts caused by solvents and like substances.

Another improved feature of the brush construction of the invention isthe manner in which the handle itself is formed so that insertion of thehandle into the previously assembled ferrule and bristle knot can bereadily and quickly effected without causing the liquid resin to beforced out around the joining surfaces of the handle and the ferrule.The joining end of the handle is provided with a novel venting means forrelieving the compression created during this assembly operation whichis formed in a simple and economical manner without adding to the numberof parts or manufacturing operations.

It is accordingly a principal object of the invention to provide new andimproved paint brushes.

Another object is to provide a new and improved brush constructionhaving the handle and ferrule component parts thereof formed fromsynthetic plastic material.

Still another object is to provide a new and improved plastic brushwherein the detrimental swelling effect of solvents thereupon has beenminimized.

A further object is to provide a plastic paint brush constructionwherein the ferrule is permanently held in tight interlocking engagementwith the handle and bristles.

A further object is to provide improved plastic handles for paintbrushes.

A still further object is to provide improved plastic ferrules for paintbrushes.

A still further object is to provide a hollow handle brush constructionwherein improved means are provided for venting the interior of suchhandle upon insertion thereof into the bristle knot and ferrulesubassernbly.

Other and different objects will in part be obvious and in part pointedout as the description, taken in conjunction with the accompanyingdrawing, proceeds.

In that drawing:

FIG. 1 is a perspective view of the paint brush in accordance with theinvention;

FIG. 2 is a perspective exploded view showing the handle and ferrulewith portions of the same cut away for purposes of clear illustration;

FIG. 3 is an end elevational view of the handle portion as shown in FIG.2;

FIG. 4 is a longitudinal cross-sectional view taken on the longitudinalplane 4-4 in FIG. 1 and looking in the direction of the arrows;

FIG. 5 is a cross-sectional view taken on line 5-5 of FIG. 4 and lookingin the direction of the arrows;

FIG. 6 is a detail view, on an enlarged scale, of an end portion of thebrush as viewed in FIG. 5;

FIG. 7 is a cross-section view taken of line 77 of FIG. 6 and looking inthe direction of the arrows;

FIG. 8 is a cross-sectional view of a modified form of the ferrule takenon line 88 of FIG. 9 and looking in the direction of the arrows;

FIG. 9 is a cross-sectional view taken on line 9-9 of FIG. 8 and lookingin the direction of the arrows;

FIG. 10 is a cross-sectional view of a further ferrule modificationtaken on line 1010 of FIG. 11 and looking in the direction of thearrows;

FIG. 11 is a sectional view taken on line 1111 of FIG. 10 and looking inthe direction of the arrows;

FIG. 12 is a cross-sectional view of still another modified form of theferrule taken on line 12-12 of FIG. 13 and looking in the direction ofthe arrows; and

FIG. 13 is a sectional view taken on line 13-13 of FIG. 12.

The complete brush assembly as shown in FIGS. 1 and 4 has as itsprincipal parts a handle 1, a ferrule 2, and a bristle knot 3. Thehandle 1 is formed of a synthetic plastic material and comprises anelongated hollow hand grip 4 flaring outwardly at one end into a curvedbase wall 5, which, in turn, has extending longitudinally outwardlytherefrom a rectangular sleeve 6 having sidewalls 8 and endwalls 7. Foradditional strength and rigidity, a pair of cross members 9 and 10extend outwardly from the base 5 and are secured to and interconnectopposing sidewalls 8. The outermost edge of the sleeve 6 has a slightinward bevel 11, and has a plurality of spaced apart and inwardly formedlugs 12 and 13 integrally formed on the end walls 7 and on the sidewalls8. These lugs are initially molded as straight longitudinalcontinuations of the sleeve walls 7 and 8, and are subsequently bentover so as to extend laterally inwardly as shown. To facilitate thisbending operation, the lugs are formed with a lesser cross sectionalthickness than the sleeve walls with the outer surface of the lugsextending flush with the outer surface of the sleeve to form ledges 17when the lugs are bent inwardly as shown in FIGS. 6 and 7. The junctionof the sleeve 6 and the curved base wall 5 is surrounded by alongitudinally outwardly opening channel 14 which has a bottom 15 formedby a portion of said base wall 5, and inner and outer sides formed bythe outer surface of sleeve 6 and a lip 16 laterally spaced from saidsleeve and secured atone end to the base wall 5. For purposes more fullyexplained hereafter a wall of the sleeve 6 has formed therein a slot 23extending longitudinally inwardly from the free edge 11 to a pointspaced from the lip 16 of channel 14.

The ferrule 2 is preferably molded of a synthetic plastic material andis shown in detail in FIGS. 2 through 7 as being a hollow member havingboth ends open and having opposing pairs of side walls 18 and 19. Theferrule 2 has a rectangular cross sectional configuration correspondingto the cross sectional configuration of the handle sleeve 6 and has aninterior surface so dimensioned so as to snugly surround the outersurface of that sleeve. The ferrule is substantially longer than thesleeve 6 and terminates at its outer or bristle end in a crosssectionally thickened lip 20, which has an end surface 21 and anelongated interior surface 22. The inner surface 24 of the lip adjacentto the inner surface of sides 18 and 19 is beveled as clearly shown inFIGS. 6 and 7 and forms a relatively sharp inner edge 25 at the point ofintersection of surfaces 22 and 24. Also formed on the interior surfaceof the ferrule 2 is a pair of opposed longitudinally extending ribs 26,preferably centrally positioned on the interior surfaces of the ferrulewalls 19. Although the lateral inward extent to which the ribs 26protrude, many vary within limits, it is desirable from a manufacturingview point, that the ribs not extend beyond the lateral interior lipsurface 22.

The assemblying of the various components into a finished brushconstruction is carried out by first inserting the bristle knot 3, whichis suitably performed and provided with spacer strips as shown at 27 inFIG. 7, into the ferrule 2 in such a manner that the ends 28 of thebristles are positioned in alignment with the edge 25 of the lip 20. Theenlarged gripping area presented by the lip surface 22 acts to hold thebristles firmly during this stage of the manufacturing process. Thisparticular feature has overcome what has become a problem in the priorart constructions since the bristles now commonly made from nylon arenot effectively frictionally held by a narrow relatively smooth plasticsurface. For this reason the surface 22 has been elongated, thispresenting a greater holding area for the bristle end portions. Also thelengthened surface 22 helps to prevent the bristles from flaringlaterally outwardly at the ferrule end 21. Such outward flaring isundesirable in the paint brush art both in terms of functions andappearance.

The next step is to inject into the open end of the ferrule a quantityof semi-liquid adhesive, a non-limiting ex ample of which is an epoxyresin. The usual amount of adhesive applied is just enough to cover theends 28 of the bristle so that the end portions of the bristles arefirmly bonded within the ferrule. After the initial adhesive applicationhas cured, this subassembly is then subjected to a further bristletrimming and finishing operation.

A second application of the semi-liquid mass 29 is then inserted in theopen end of the ferrule on top of the previous application filling theferrule to a level substantially above the lugs 26. The sleeve 6, of thehandle 1 is then inserted in the ferrule, fitting snugly therewithin,and the respective parts moved longitudinally together until the innerend 32 of the ferrule abuts the bottom wall 15 of channefl 14 on thehandle end portion. The inner end 32 of the ferrule is beveled tofacilitate the insertion of the ferrule onto sleeve 6. As the sleeve 6slides into the ferrule 2, the air confined within the sleeve and theferrule is com pressed and unless released would force the adhesive outaround the bristles and create undesirable pressure on the ferrule.However this confined air is vented through the slot 23 as the parts aremoved together. Continued movement of the sleeve into the ferrule embedsthe lugs 12 and 13 in the adhesive mass 29 when the ferrule end 32 isfully seated against the bottom 15 of the channel 14. It is to be notedhere that the two applications of adhesive above described could beconsolidated into a single applica tion without departing from the scopeof the invention. This would simply mean that the bristle finishingoperation would be performed on the completed brush rather than on theferrule and bristle subassembly. Upon final curing of the secondapplication of adhesive mass 29 a very strong hard mass is formed asshown in FIGS. 4, 6 and 7. In order to form a permanent, rigid,interlocking engagement between the bristle knot 3 and the handle 1, itis important that the adhesive mass 29 extend above and completely coverthe inturned lugs 12 and 13 thus insuring against any possibility of thelugs breaking out of the adhesive mass. This engagement is furtherstrengthened by the particular configuration assumed by the surface ofthe adhesive mass upon curing. That configuration comprises a depressedcentral portion 30 bordered by a raised peripheral portion 31 providingadded strength above the lugs where it is most meeded and decreasing inthickness toward the less critical center area where the volume of themass can be reduced without adversely affecting the structural qualitiesof the brush.

In addition to securely joining the handle 1 and the bristle knot 3, itis essential that the ferrule 2 be permanently secured to the handle intight relationship and at the same time to be securely interlocked tothe bristle knot so that lateral outward movement of any portion of thewalls of the ferrule is prevented. It is this part of the brush 1assembly which is most susceptible to the damaging effects of theordinary solvents to which the brush is ultimately subjected. Theresulting reaction of the plastic ferrule when submerged in ordinarysolvents is to swell to a greater internal dimension thus pullinglaterally away from the sides of the adhesive mass 29. Subsequent use ofthe brush when the ferrule portion is in this swelled condition causesthe ferrule to be worked away from the handle in a longitudinaldirection and of course eventually to be completely separated therefrom.Thus it can be seen that the problem is to secure the ferrule to thehandle and to the bristle knot in such a manner that both lateral andlongitudinal movement of the ferrule with respect to the handle sleevewill be effectively precluded. It has by now become recognized that thedegree of adhesion which exists between the mass 29 and the interiorsurface of the ferrule 2 is wholly inadequate for this purpose. Thesolution to this problem lies in the novel construction disclosed inthis invention as illustrated particularly in FIGS. 6 and 7 encases thelugs 12 and 13 but also completely encases the ribs 26. The result is aportion of the permanently hardened mass as indicated at 33 in FIG. 7abutting the interior surface of the ferrule 2 and lying between theupper surface of the rib 26 and the downwardly facing surface of thelugs 12 and 13. Also abutting the interior surface of the ferrule is aportion 34 of the adhesive mass lying below the lower surface of the lug26 and extending at 35 into and filling the V-shaped groove formed bythe beveled surface 24.

From the foregoing it can be readily seen that lateral outward expansionof the ferrule is prevented throughout its inner peripherial edge by thelip 16 and throughout its outer periphcrial edge by the adhesive massportion 35 which is interlocked against the beveled surface 24. So longas the side walls of the ferrule are restrained from moving laterallyaway from the handle sleeve 6, longitudinal movement of the ferrule awayfrom the handle is effectively prevented by the lower surface of rib 26which bears against the adhesive mass portion 34. This mechanicalinterlock between the hardened adhesive mass 29 and the ferrule 22prevents separation of the brush assembly and the ferrule in bothlateral and longitudinal directions. At the same time this improvedconstruction is brought about without complicating to any material exentthe simple manufacturing process normally employed in molding therespective plastic parts.

The ferrule may be molded of the same synthetic plastic material as thatfrom which the handle is molded if desired, without departing from thescope of the invention. However, to further enhance the solventresistant characteristic of the brush of the invention it has been foundthat an improved construction results from molding the ferrule of aplastic material having somewhat greater solvent resistance than thehandle. A nonlimiting example is the combination of an acetal ferruleand a polypropylene handle. The improved results in this respect flowfrom the fact that the more solvent resistance acetal material fromwhich the ferrule is molded is characterized by superior dimensionalstability and hence less susceptible to severe swelling upon submersionin chemically active organic solvents, cleaners, thinners and the like.The handle, however, is not subjected to quite the same abuse as is theferrule in this respect. Swelling of the handle component withinreasonable limits does not adversely effect the overall brushconstruction as does swelling of the ferrule. When a brush soconstructed is submerged in an organic solvent for a prolonged periodthis difference is dimensional stability of the handle and ferrule hasan advantage. Since the handle end portion swells or expands more thanthe ferrule 2, the engagement between the two parts actually becomestighter upon swelling, thus further insuring against their separation.The polypropylene material from which the handle is formed also resultsin both a cost and a manufacturing advantage in that it is easier tomold and the operation of bending over the lugs 12 and 13 is facilitatedby the use of the somewhat softer material.

A modified ferrule 40 is shown in FIGS. 8 and 9 which is similar in allrespects to the ferrule 2 of the preferred embodiment with the exceptionthat a peripheral groove 41 is formed in the interior surface of thewalls 7 and 8 slightly above the beveled surface 24 for receiving aportion of the adhesive mass to provide an additional interlocking jointbetween the adhesive mass and the side walls of the ferrule. It is to benoted that the V-shaped groove formed by the beveled surface 24 is alsoshown as extending peripherally in this embodiment.

FIGS. and 11 depict another modification wherein the ferrule 51 isformed with a plurality of spaced recesses 51 formed in the interiorsurface of the side walls and ex tending peripherally of said ferrulewhich provide the required mechanical interlock.

In FIGS. 12 and 13 a still further modified ferrule 60 is shown having aplurality of spaced projections 61 which extend from the interiorsurface of the side walls and which serve to lock the ferrule to thehandle.

Since further variations and modifications in the brush construction asdescribed in the foregoing specification and shown in the accompanyingdrawing may readily suggest themselves to those skilled in the art, itis to be understood that the same can be made without departing from thespirit and scope of the invention. It is accordingly intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted in an illustrative and not a limitingsense.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. In brush construction, a hollow, one-piece handle molded of syntheticplastic material having an elongated hand grip portion terminating atone end in a laterally out- Wandly flared base wall, a hollowsubstantially rectangular sleeve extending longitudinally outwardly fromsaid base wall and terminating in a free end, said sleeve includingopposed side walls and opposed end walls, a laterally extending shouldersurrounding said sleeve, bristles adhesively bound together adjacent oneend in an adhesive mass and extending longitudinally outwardly of saidsleeve, a plurality of laterally extending adhesive engaging surfacesprovided on said sleeve for effecting interlocking engagement betweensaid sleeve and said adhesive mass, a portion of said adhesive massinterposed between said one end of said bristles and said free end ofsaid sleeve, a hollow tubular ferrule having an inner end and an outerend and including opposed side walls and opposed end walls engaged aboutsaid sleeve, said ferrule extending longitudinally outwardly of saidsleeve so as to surround said adhesive mass and said bound end of saidbristles and structural interlocking means including two separateferrule surfaces integrally formed on the inner surface of said ferruleside walls positioned longitudinally outwardly of said sleeve end toeffect lateral and longitudinal interlocking engagement with saidadhesive mass whereby said ferrule inner end is held againstdisplacement away from said shoulder and said ferrule outer end is heldin contact with said bristles.

2. In brush construction as in claim 1, wherein a portion of saidadhesive mass extends laterally outwardly between said two surfaces.

3. In brush construction, a hollow, one-piece handle molded of syntheticplastic material having an elongated hand grip portion terminating atone end in a laterally outwardly flared base wall, a hollowsubstantially rectangular sleeve extending longitudinally outwardly fromsaid base wall and terminating in a free end, said sleeve includingopposed side walls and opposed end walls, a laterally extending shouldersurrounding said sleeve bristles adhesively bound together adjacent oneend in an adhesive mass and extending longitudinally outwardly of saidsleeve, a plurality of laterally extending adhesive engaging surfacesprovided on said sleeve for effecting interlocking engagement betweensaid sleeve and said adhesive rnass, a portion of said adhesive massinterposed between said one end of said bristles and said free end ofsaid sleeve, a hollow tubular ferrule having an inner end and an outerend and including opposed side walls and opposed end walls engaged aboutsaid sleeve, said ferrule extending longitudinally outwardly of saidsleeve, so as to surround said adhesive mass and said bound end of saidbristles, first structural interlocking means integrally formed on theinner surface of said ferrule side walls posi tioned longitudinallyoutwardly of said sleeve end and longitudinally inwardly of said ferruleouter end to effect lateral interlocking engagement with a first portionof said adhesive mass and second structural interlocking meansintegrally formed on the inner surface of said ferrule side wallspositioned longitudinally outwardly of said sleeve end andlongitudinally inwardly of said ferrule outer end to effect longitudinalinterlocking engagement with a second portion of said adhesive masswhereby said ferrule inner end is held against longitudinal displacementaway from said shoulder and said ferrule outer end is laterally held incontact with said bristles.

4. In brush construction as in claim 3, wherein said first adhesiveportion has a ferrule engaging surface angularly disposed with respectto a ferrule engaging surface on said second adhesive portion.

References Cited UNITED '8 10/1958 Hardman et 'al. -15193 4/1964 Daw15192 11/1964 Hardman et al. 15192 7/1965 Weiss et al. 15-192 2/1966Malpas 15--193 FOREIGN PATENTS 3/ 1964 Australia. 12/ 1955 Belgium.

6/1962 Ger-many. 2/ 1962 Great Britain. 7/ 1963 Great Britain.

CHARLES A. WlLLMUTI-I, Primary Examiner.

' PETER FELDMAN, Assistant Examiner.

1. IN BRUSH CONSTRUCTION, A HOLLOW, ONE-PIECE HANDLE MOLDED OF SYNTHETICPLASTIC MATERIAL HAVING AN ELONGATED HAND GRIP PORTION TERMINATING ATONE END IN A LATERALLY OUTWARDLY FLARED BASE WALL, A HOLLOWSUBSTANTIALLY RECTANGULAR SLEEVE EXTENDING LONGITUDINALLY OUTWARDLY FROMSAID BASE WALL AND TERMINATING IN A FREE END, SAID SLEEVE INCLUDINGOPPOSED SIDE WALLS AND OPPOSED END WALLS, A LATERALLY EXTENDING SHOULDERSURROUNDING SAID SLEEVE, BRISTLES ADHESIVELY BOUND TOGETHER ADJACENT ONEEND IN AN ADHESIVE MASS AND EXTENDING LONGITUDINALLY OUTWARDLY OF SAIDSLEEVE, A PLURALITY OF LATERALLY EXTENDING ADHESIVE ENGAGING SURFACESPROVIDED ON SAID SLEEVE FOR EFFECTING INTERLOCKING ENGAGEMENT BETWEENSAID SLEEVE AND SAID ADHESIVE MASS, A PORTION OF SAID ADHESIVE MASSINTERPOSED BETWEEN SAID ONE END OF SAID BRISTLES AND SAID FREE END OFSAID SLEEVE, A HOLLOW TUBULAR FERRULE HAVING AN INNER END AND AN OUTEREND AND INCLUDING OPPOSED SIDE WALLS AND OPPOSED END WALLS ENGAGED ABOUTSAID SLEEVE, SAID FERRULE EXTENDING LONGITUDINALLY OUTWARDLY OF SAIDSLEEVE SO AS TO SURROUND SAID ADHESIVE MASS AND SAID BOUND END OF SAIDBRISTILES AND STRUCTURAL INTERLOCKING MEANS INCLUDING TWO SEPARATEFERRULE SURFACES INTEGRALLY FORMED ON THE INNER SURFACE OF SAID FERRULESIDE WALLS POSITIONED LONGITUDINALLY OUTWARDLY OF SAID SLEEVE END TOEFFECT LATERAL AND LONGITUDINAL INTERLOCKING ENGAGEMENT WITH SAIDADHESIVE MASS WHEREBY SAID FERRULE INNER END IS HELD AGAINSTDISPLACEMENT AWAY FROM SAID SHOULDER AND SAID FERRULE OUTER END IS HELDIN CONTACT WITH SAID BRISTLES.